• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.12
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• pp.3025-3032
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• 1996

A fast algorithm for the restoration of an images based on chain codes description using y-axis partition of the starting and ending ponts. The algorithm is to convert the chain codes description into the two y-axis partitions by proposed look-up table. It reduces the size of column elements as a half in y-axis partition. this technique is computationally faster than Shih's methods. comparision of the proposed method and Shih method is also provided.

• International Journal of Computer Science & Network Security
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• v.21 no.7
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• pp.359-364
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• 2021

In recent years Hadoop usage has been increasing day by day. The need of development of the technology and its specified outcomes are eagerly waiting across globe to adopt speedy access of data. Need of computers and its dependency is increasing day by day. Big data is exponentially growing as the entire world is working in online mode. Large amount of data has been produced which is very difficult to handle and process within a short time. In present situation industries are widely using the Hadoop framework to store, process and produce at the specified time with huge amount of data that has been put on the server. Processing of this huge amount of data having small files & its storage optimization is a big problem. HDFS, Sequence files, HAR, NHAR various techniques have been already proposed. In this paper we have discussed about various existing techniques which are developed for accessing and storing small files efficiently. Out of the various techniques we have specifically tried to implement the HDFS- HAR, NHAR techniques.

• PNF and Movement
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• v.15 no.1
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• pp.35-40
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• 2017

Purpose: The purpose of this study was to determine the immediate effects of using the proprioceptive neuromuscular facilitation (PNF) contract-relax technique in the close kinetic chain position on the gait ability and gastrocnemius muscle tone of stroke patients. Methods: The subjects were patients who had strokes due to cerebrum infarction and hemorrhage. The subjects participated in exercise with the PNF contract-relax technique in the standing-on-elbow position with a high table, and the affected lower leg was placed in the posterior position. The PNF contract-relax technique was applied at the position in which the ankle plantar-flexors were in a sufficiently elongated position. After performing twice in each range, while the muscle was elongated, the affected side was moved further back and a new range was set. In each session, the time of contraction was set to 8 seconds, and the resting time was set to 5 seconds; however, if the patient felt tired, they received more resting time during the intervention. The Myoton Pro and 10 m walking test were used to measure the muscle tone and gait ability both pre- and post-intervention. Results: After participating in the program, the muscle tone decreased and the gait ability improved in the ankle plantar-flexors, as determined by the Myoton Pro and 10 m walking test. Conclusion: The PNF contract-relax technique can help to decrease muscle tone in ankle plantar-flexors with hypertonus and increase the gait ability in stroke patients.

• Journal of Korea Society of Digital Industry and Information Management
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• v.11 no.3
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• pp.69-77
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• 2015

MANET is composed of only the mobile nodes have a limited transmission range. The dynamic topology by the frequent movement of nodes makes routing difficult and is also cause exposed to security vulnerabilities. In this paper, we propose the security routing technique consisted of mechanism of two steps in order to respond effectively to attack by the modification of the routing information and transmit secure data. The hierarchical structure is used and the authentication node that issues the key of the nodes within each cluster is elected in this proposed method. The authentication node manages key issues and issued information for encrypting the routing information from the source node. The reliability value for each node is managed to routing trust table in order to secure data transmission. In the first step, the route discovery is performed using this after the routing information is encrypted using the key issued by the authentication node. In the second step, the average reliability value of the node in the found path is calculated. And the safety of the data transmission is improved after the average reliability value selects the highest path. The improved performance of the proposed method in this paper was confirmed through comparative experiments with CBSR and SEER. It was confirmed a better performance in the transmission delay, the amount of the control packet, and the packet transmission success ratio.

• Journal of Internet Computing and Services
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• v.21 no.1
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• pp.179-190
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• 2020

In the Unix-like system environment, the GOT overwrite attack is one of the traditional control flow hijacking techniques for exploiting software privileges. Several techniques have been proposed to defend against the GOT overwrite attack, and among them, the Full Relro(Relocation Read only) technique, which blocks GOT overwrites at runtime by arranging the GOT section as read-only in the program startup, has been known as the most effective defense technique. However, it entails loading delay, which limits its application to a program sensitive to startup performance, and it is not currently applied to the library due to problems including a chain loading delay problem caused by nested library dependency. Also, many compilers, including LLVM, do not apply the Full Relro technique by default, so runtime programs are still vulnerable to GOT attacks. In this paper, we propose a GOT protection scheme using the Control Flow Integrity(CFI) technique, which is currently recognized as the most suitable technique for defense against code reuse attacks. We implemented this scheme based on LLVM and applied it to the binutils-gdb program group to evaluate security, performance and compatibility. The GOT protection scheme with CFI is difficult to bypass, fast, and compatible with existing library programs.

• Journal of Korean Society on Water Environment
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• v.26 no.1
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• pp.116-124
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• 2010

While groundwater is the major source for drinking and irrigation purposes, arsenic (As) contamination of groundwater is a serious issue in Bangladesh. With a view to reduce As contamination in drinking water the guideline value recommended for Bangladesh is 0.05 mg/L. We assessed groundwater As in an As-affected Sadar Upazilla (small administrative unit) in the District (administrative unit) of Chapai Nabwabganj during 2006, where 50% hand tube well water were above the recommended limit (0.05 mg/L) during dry season. Almost 20% tube well waters were above the recommended limit during rainy season, perhaps due to the dilution of water table. The groundwater in Bangladesh contaminates surface soils and plants thereby As entering the food chain. In 2005, we examined the As levels in different rice varieties grown in different Districts of Bangladesh and the As concentrations in rice grain ranged from 0.07~1.12 mg/kg while the concentrations in 3 rice varieties were above the recommended limit (1 mg/kg rice grain) and the maximum concentration was 1.12 mg/kg rice grain in the rice variety BR 11. With few exceptions, the As content of rice grain in Bangladesh is not considered to be concentration of greater health concern as yet. We also observed enhanced root uptake, efficient root-to shoot translocation, and a much elevated tolerance through internal detoxification all contribute to As hyperaccumulation in a plant, ladder brake fern (Pteris vittata L.). But the phytoremediation technique might not be an appropriate tool to reduce the As calamity in the vast areas of Bangladesh. To mitigate the As problem of Bangladesh, better coordination among governmental agencies and many other organizations will be required to combat the disaster.